Ccna 3, Chapter 6

Front 1

what is an ospf area

Back 1

group of routers that share the same link-state information in their link-state databases

Front 2

2 layers of multilayer OSPF

Back 2

backbone

regular

Front 3

describe backbone area of multilayer ospf 4

Back 3

primary function fast and efficient movement of ip packets

interconnets with other ospf types

no end users

aka area 0

Front 4

describe regular area of multilayer ospf 3

Back 4

connects users and resources

set up along functional or geographical groupings

does not allow traffic from another area to use its links to reach other areas

Front 5

what is interarea traffic

Back 5

all traffic moving from one area to another area via the backbone

Front 6

router and area guidelines 3

Back 6

area should have no more than 50 routers

router should not be in more than 3 areas

a single router should not have more than 60 neighbors

Front 7

4 types of ospf routers

Back 7

internal

backbone

area border router

autonomous system boundar router

Front 8

describe ospf internal router

Back 8

all of the interfaces are in the same area

Front 9

describe backbone ospf router

Back 9

router in the backbone area,

Front 10

abr stands for

Back 10

area border router

Front 11

describe abr ospf router 3

Back 11

router that has interfaces attached to multiple areas

exit points for an area

can be configured to summarize routing information

Front 12

asbr stands for

Back 12

autonomous system boundary router

Front 13

describe asbr ospf router

Back 13

router has at least 1 interface attached to an external network

can import non-ospf network info to the network

Front 14

what is route redistribution

Back 14

the import of non-ospf network information to an ospf network and visa versa

Front 15

when does route redistribution occur

Back 15

when an asbr connects different routing domains and configures tham to exhange and advertise routing into between the 2 groups

Front 16

lsa type 1

Back 16

router lsa

Front 17

lsa type 2

Back 17

network lsa

Front 18

lsa type 3 and 4

Back 18

summary lsa

Front 19

lsa type 5

Back 19

as external lsa

Front 20

type 1 lsa aka

Back 20

router link entries

Front 21

what do type 1 lsas contain

Back 21

a list of the directly connected interfaces

link types

link states

Front 22

type of lsa all routers generate

Back 22

type 1

Front 23

do type 1 lsas go beyond an abr

Back 23

no

Front 24

how are type 1 lsas identified

Back 24

by the router id of the originating router

Front 25

where does a type 2 lsa only exist

Back 25

multiaccess and non-broadcast multiaccess networks

Front 26

what does a type 2 lsa contain

Back 26

router id and ip address of the dr

router id of all other routers on the multiaccess segment

Front 27

purpose of type 2 lsa

Back 27

give other routers information about multiaccess networks within the same area

Front 28

are type 2 lsas broadcast outside of the area where they originate

Back 28

no

Front 29

type 2 lsa aka

Back 29

link entries

Front 30

If there are no multiarea routers in an area, will type 2 lsas be generated

Back 30

no

Front 31

what are type 3 lsas used for

Back 31

used by abrs to advertise networks from other areas.

Front 32

how is a type 3 lsa created

Back 32

abrs collect type 1 lsas until the area has converged. it then creates a type 3 lsa from the areas that it has learned about.

Front 33

what are type 4 and 5 lsas for

Back 33

used to identify an asbr and advertise external networks into an ospf routing domain

Front 34

when is a type 4 summary lsa generated

Back 34

only when an asbr exists within an area.

Front 35

what does a type 4 lsa do

Back 35

identifies the asbr and provides a route to it

Front 36

how does a router know to build a type 4 lsa

Back 36

it recognizes the e bit that the asbr sends. it then builds the type 4 lsa to let other routers know the route to the asbr.

Front 37

what do type 5 lsas describe

Back 37

routes to networks outside the ospf autonomous system

Front 38

type 5 lsas aka

Back 38

autonomous system external lsa

Front 39

which router generates a type 5 lsa

Back 39

asbr

Front 40

what type of router generates a type 4 lsa

Back 40

abr attached to asbr

Front 41

what does O mean in a routing table

Back 41

the route is intra-area

Front 42

what does O IA mean in a routing table

Back 42

route is interarea

Front 43

what does O E1 or O E2 mean in a routing table

Back 43

External type 1 or 2 routes

Front 44

1st calculation ospf does and it's letter designation in the routing table

Back 44

best paths to destination within their area (intra-area), type 1 and 2 lsas, O

Front 45

2nd calculation ospf does and its letter designation in the routing table

Back 45

best paths to other areas in the network, type 3 and 4 lsas, O IA

Front 46

3rd calculation ospf does and its letter designation in the routing table

Back 46

best paths to the external autonomous system, type 5 lsas, O E1 or O E2, depending on the onfiguration

Front 47

what is interarea route summarization

Back 47

occurs on abrs and applies to routes from within each area

Front 48

what is external route summarization

Back 48

specific to external routes that are injected into ospf via route redistribution, only done by asbrs